反应详情

Methyl 4-(3-methylphenoxy)-6-methoxy-pyrimidin-5-yl-acetate (12.1 g, 42 mmol)is dissolved in a mixture of 1,2-dimethoxyethane (120 ml) and methyl formate (50 ml). Sodium hydride (2.5 g, 80% in oil, 84 mmol) is added in one portion, the temperature being kept at room temperature. After 5 hours dimethylsulfate (6.6 ml, 70 mmol) is added with cooling. After an additional 5 hours the reaction mixture is diluted with ether and washed with brine. Drying and chromatography on silicagel (eluant: hexane/ethyl acetate 1:1) gives the E-isomer of methyl α-[4-(3-methylphenoxy)-6-methoxy-pyrimidin-5-yl)-β-methoxyacrylate as a crystalline solid, m.p. 107° C.

1. custombeing kept at room temperature
2. temperaturewith cooling
3. washwashed with brine
4. customDrying